1. Field of the Invention
The present invention generally relates to a remote control system and, more particularly, it relates to a remote control system using remote controllers using infrared rays for transmission paths of control codes.
2. Description of the Related Art
In a first prior art remote control system, since remote controllers have been developed to control a single equipment containing a signal receiver by means of a single signal transmitter, they are typically used as pairs comprising a transmitter and a receiver. This will be explained later in detail.
In the first prior art remote control system, however, since a single equipment containing a receiver is controlled by means of a single transmitter, a start code, an identification code and its inverted code and a stop code each time when transmitting 1 byte data, such a data transmission technique is cumbersome and poorly efficient when a large amount of data is transmitted.
In a second prior art remote control system (see JP-A-62-132494), a cascade configuration is adopted for two equipments, so that one of the equipments incorporating a receiver is connected by way of a signal line to the other of the equipments. This will also be explained later in detail.
In a third prior art remote control system (see JP-A-6-90484), an optical fiber and a light emitting plate for generating an infrared signal are provided between two equipments. Also, a light receiving section is provided in the lower order equipment. This will also be explained later in detail.
In the second and third prior art remote control systems, however, since they are arranged for one-way communication, these systems cannot simply be applied to bidirectional infrared communication because it can give rise to an arbitration-disabled status in a plurality of transmitters as they mask their own respective data to be transmitted and the received data.
In a fourth prior art remote control system (see JP-A-5-41693), an infrared communication system adapted only to half-duplex communication is so arranged that the transmission data is temporarily compressed and transmitted from a transmitter to a receiver as time-sharing data and the receiver recovers the original data by temporarily extending the received data. A similar process is carried out in the reverse direction and data are transmitted on a time-sharing basis as they are inserted into the gaps of the above time-sharing data so that apparently the system is adapted to full-duplex communication.
In the fourth prior art remote control system, although bidirectional communication may be realized, it is heavily lopsided on bidirectional communication and provides only a bidirectional communication path for a single set of a receiver and a transmitter so that it cannot control any existing remote control systems and has no upper compatibility.
In a fifth prior art remote control system (see JP-A-6-98383), a signal receiving time is made long relative to a signal transmitting time and the transmitter randomly changes the interval for transmitting data or the time for suspending data transmission, whereas the receiver is provided with means for avoiding any overlapping of transmitted data and selecting data containing the ID code of itself so that the problem that arises when data are transmitted from a plurality of remote controllers simultaneously can be effectively avoided.
In the fifth prior art remote control system, however, the control is complex.
Additionally, an infrared data communication system involving the use of an electronic notebook or a notebook-sized personal computer is known. The IrDA (Infrared Data Association) Standards are known as standards for such infrared data communications. The IrDA standards represent a system for infrared local area networks (LAN) and employ a protocol for high level data link procedures specifically improved for radio data communication for the data link layer to realize features including automatically specifying a communication path, transferring the control initiative and specifying an automatic ID for newly added equipment.
However, the remote control system using the IrDA standards is expensive and is not adapted to the technological field of remote control. Additionally, such a system is not compatible with other known remote control systems.